Method of removing scratches and damages from the saddle shaped outer surface of the inner race for constant velocity axle joint of a car

ABSTRACT

A novel system of removing scratches and damages from the saddle shaped outer surface of an inner race for a constant velocity axle joint of a car is comprised of an “O”-ring shaped sandpaper comprised of a flexible ring and an abrasive surface developed by adhering powders of abrasive materials such as aluminum oxide, ceramic aluminum oxide, aluminum zirconia, zirconia and silicon carbide to the outer surface of the flexible ring. The “O”-ring shaped surface of the sand paper of this invention fits the saddle shape of the outer surface of the inner race for constant velocity axle joint of a car. The sandpaper of this invention is mounted on a conventional belt sander equipped with three concave grooved belt wheels. The method of this invention enables even grinding and polishing of the saddle shaped outer surface of the inner race, which was impossible by the prior arts.

[0001] This invention relates to a novel method of removing scratches from the saddle shaped outer surface of an inner race for constant velocity axle joint of a car.

1. FIELD OF THE INVENTION

[0002] A novel sandpaper for removing scratches and damages from the saddle shaped outer surface of the inner race for constant velocity axle joint is invented. The sandpaper is of “O”- ring shape and mounted on a conventional belt sander equipped with three-grooved belt wheel.

2. DESCRIPTION OF THE PRIOR ARTS

[0003] The prior art of removing scratches from a saddle shaped outer surface of an inner race for constant velocity axle joint of used car is using a hand grinder of flat surface. It is impossible to grind and polish the scratched surface evenly by the prior art.

[0004] Another prior art of girding and polishing curvature surfaces with abrasive belt is taught in U.S. Pat. No. 6,095,909 to Chenu which illustrates an abrasive belt machine tool for machining cylindrical bearing surface on shafts. The abrasive belt 9 passes in front of the concave surfaces 6 a and 6 b of the two jaws 5. The belt grinds the convex surface of the bearing, not the concave saddle surface.

[0005] U.S. Pat. Nos. 5,651,719 and 5,224,300 to Pineau illustrate a machine for the abrasive machining of cylindrical parts, on which the parts to be machined are driven in rotation and in axial transnational motion by supporting and driving means. Prior arts are for machining only the convex surface of metal bearing.

[0006] U.S. Pat. No. 5,707,279 to Mitchell, et al. illustrates an abrasive tool with a tubular sleeve of exteriorly coated abrasive which has an axial length and an inside diameter. It is designed to fabricate the inner surface of tubular metal structure.

[0007] On the other hand, U.S. Pat. No. 4,039,303 to Yasushi, et al. teaches a method for manufacturing an abrasive tubular structure formed of cloth and paper and particularly the construction of that tube. The prior art of the abrasive tubes are used to grind plywood sheets, aluminum, stainless steel sheets, etc., for the purpose of smoothing the surface thereof. Their tubular abrasive band is straight and is not designed for a saddle shape surface.

[0008] None of the prior arts provides a method to grind and polish a saddle shape metal surface.

SUMMARY OF THE INVENTION

[0009] It is the purpose of this invention to provide a novel method of removing scratches and damages from the saddle shaped outer surface of an inner race for constant velocity axle joint and a system for that purpose. An “O”-ring shaped sandpaper is comprised of a flexible ring and an abrasive surface developed by adhering powders of abrasive materials, including but not limited to, aluminum oxide, ceramic aluminum oxide, aluminum zirconia, zirconia and silicon carbide to the outer surface of the flexible ring. The convex shaped surface of the sand paper of this invention fits the saddle shape of the outer surface of the inner race for constant velocity axle joint. The sandpaper of this invention is mounted on a conventional belt sander equipped with three concave grooved belt wheels. The method of this invention enables even grinding of the saddle shaped outer surface of the inner race, which was impossible by prior arts.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1a is a schematic drawing of an inner race for constant velocity axle joint of a car.

[0011]FIG. 1b is a side view of an inner race.

[0012]FIG. 1c is an over view of an inner race.

[0013]FIG. 2a is a perspective view of traditional scratch removing method.

[0014]FIG. 2b is a side view of FIG. 2a.

[0015]FIG. 3 is a perspective view of the “O”-ring type abrasive belt of this invention.

[0016]FIG. 4 is a cross sectional view of the “O”-ring type abrasive belt of this invention.

[0017]FIG. 5 is a schematic drawing of the scratch removing methods of this invention.

[0018]FIG. 6 is a schematic drawing showing how the scratch is removed.

[0019]FIG. 7 is a front view of the concave grooved belt wheels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020]FIG. 1a is a schematic drawing of an inner race for constant velocity axle joint of a car. Ball (10) of bearing is mounted on the saddle shape surface (11) of the inner race (12). FIG. 1b and FIG. 1c are side- and over-view of the saddle shape surface, respectively. The side shape of saddle surface (11) is convex and over view of the saddle surface (11) is concaved. It is very complex geometry to be evenly grinded and polished by hand.

[0021]FIG. 2a is a perspective view of traditional scratch removing method. A sheet of sand paper/solid grind (13) is used to remove a scratch/damage (14) on the concave surface (11) of the inner race (12). FIG. 2b is a side view of FIG. 2a. When a sheet of sand paper/hand grinder (13), driven by the air tool (13A), moves along the surface (11), the scratch (14) becomes broader than before. The broadened scratch (14′) may cause severe problem to the constant velocity axle joint of a car. It is very time consuming and tedious job to make the surface (11) as smooth saddle shape as before the scratch was developed.

[0022]FIG. 3 is a perspective view of the “O”-ring type abrasive belt (20) of this invention. The base of this “O”-ring (15) is comprised of fabric layer (16) and elastic layer (17). Particles of abrasive materials (18), including but not limited to, aluminum oxide, ceramic aluminum oxide, aluminum zirconium, zirconium and silicon carbide are adhered on the surface of the “O”-ring (15).

[0023]FIG. 4 is a cross sectional view of the “O”-ring type abrasive belt (20) of this invention. The center is filled with the fabric layer (16) and elastic layer (17) locates between the fibers. Particles of abrasive material (18) are adhered to the outer surface of the “O”-ring (15) by applying adhesives and hot melt adhesion.

[0024]FIG. 5 is a schematic drawing of the scratch removing methods of this invention. The inner race (12) with scratch (14) supported by a worker's hand (19) approaches to the “O”-ring shaped abrasive belt (20) of this invention rotating to the indicated direction, driven by the sander equipped with three sander wheels (21), (22) and (23).

[0025]FIG. 6 is a schematic drawing showing how the scratch is removed. Due to the two sander wheels (21), (22) whose front line locate behind the saddle shaped surface (11), the “O”-ring type abrasive belt is bent and fit along the surface of the saddle shaped surface (11). Comparing with FIG. 2, it is clear that the belt grinds and polishes the saddle shaped surface (11) evenly throughout the height of the inner race (12). As a result of such tight fitting along the saddle shaped surface, the curvature of the finished saddle shaped surface is the same as the surface (11) before the scratch was developed.

[0026]FIG. 7 is a front view of the sander wheels. The groove (24) of the wheel (23) has concaved shaped fitting the “O”- ring shaped abrasive belt (20).

[0027] The best mode of this invention is to use a “O”-ring type abrasive belt comprised of fiber mesh support coated with rubber, and hot melt adhered abrasive material of zirconium. 

What is claimed is:
 1. A novel system of removing scratches and damages from the saddle shaped outer surface of an inner race for constant velocity axle joint of a car and a system, including an “O”-ring shaped sandpaper, being comprised of a flexible “O”-ring and an abrasive surface developed by adhering powders of abrasive materials applied to the outer surface of the flexible “O”-ring, and a band sander equipped with three concave grooved belt wheels.
 2. The abrasive material, in claim 1, is aluminum oxide.
 3. The abrasive material, in claim 1, is ceramic aluminum oxide.
 4. The abrasive material, in claim 1, is aluminum zirconia.
 5. The abrasive material, in claim 1, is zirconia.
 6. The abrasive material, in claim 1, is silicon carbide. 